EN
Santa Cruz Ground-dove Alopecoenas sanctaecrucis



Justification

Justification of Red List Category
This ground-dove remains extremely poorly known. It is precautionarily classified as Endangered, based on the assumption that after a recent catastrophic event its population is very small and suspected to be declining further. However, as the population size is only roughly estimated and no data on the rate of decline are currently available, the species might warrant further uplisting when clearer re-assessment becomes possible.

Population justification

The population size has previously been listed as 600-1,700 mature individuals. It is probably now much smaller as a result of the losses from Tinakula, and given that it was only a rough estimate, the population size may have been smaller than this in the first place. As the species is only very rarely recorded on Espiritu Santo, the population size there could be very small. Using the lowest population densities of former congeners (genus Gallicolumba) and assuming only a proportion of its range in Espiritu Santo is occupied would give a population size there in the range 210-1,055 mature individuals.

The recent survey on Tinakula found 15 individuals – 11 males and 4 females, although it is not certain whether these were all mature individuals (although Baptista et al. [2018] describe a different plumage colouration in juveniles, so it is possible that all counted individuals may be mature), and it is not known whether this is the total population on the island, or whether there may be some other individuals present still. The skew in the sex ratio of individuals found means that a lower population size should be used (per IUCN Standards and Petitions Subcommittee 2017), but again it is unknown whether it is possible for all individuals in this very small population to successfully breed. Given the uncertainty, it is very tentatively suggested that the population size for Tinakula be assessed as 8-15 mature individuals. This would then give an overall global population in the range 218-1,070 mature individuals, equating roughly to 300-1,600 individuals in total.

Trend justification
While the eruption of the volcano on Tinakula in 2017 has caused a large one-off population reduction, any remaining population on Espiritu Santo is also likely to be undergoing a continuing decline due to the ongoing threats of introduced mammals and habitat loss.

Distribution and population

Alopecoenas sanctaecrucis is currently known for certain only from Tinakula in Temotu province (Santa Cruz Islands), Solomon Islands, and Espiritu Santo, Vanuatu (Bregulla 1992, D. Gibbs in litt 1999, Pierce 2014).
Until recently, the largest part of the population was found on Tinakula (8 km2), which is currently free of rats, cats and feral pigs and only seasonally inhabited, but has yellow crazy ants (Anaplolepis gracilipes) (Pierce 2014). However, in 2017, trappers went to Tinakula and collected a large number of individuals from the population there, some of which ended up in the cagebird market, although some were confiscated in the Solomon Islands before they could leave the country (N. Collar in litt. 2017). Then in October 2017, the Tinakula volcano erupted, destroying a large part of the island, and potentially killing a large proportion of the species's population on the island (N. Collar in litt. 2017). A survey that took place in mid-December 2017 on Tinakula found some individuals still living in the wild on the island. In total this survey located only 11 male and 4 female Santa Cruz Ground-doves (which could potentially equate to the whole population on the island), while 109 individuals rescued from trade are now being safely kept in captivity in the Solomon Islands (OceansWatch 2017, Assomull 2017). 
It survives on Espiritu Santo (3,955 km2) which has extensive forest. Recent sightings include some birds seen in 1972, one in 1985, two sightings of one to two birds at 300-400 m in 2006 (Barré et al. 2011), three birds heard on Peak Santo in 2008, one bird heard on Peak Santo in 2009 (G. Dutson in litt. 2009) and two sightings of probably the same bird on Mt Tabwesawema in late 2017/early 2018 (M. O'Brien in litt. 2018). Unconfirmed recent incidental sightings of the species on Espiritu Santo have been reported at two sites in the mountains of west Espiritu Santo (S. Totterman in litt. 2010), in Vatthe Conservation Area in the north side of the island (S. Maturin to M. O'Brien in litt. 2010) and on the high mountain ranges of Penoru village of north western Espiritu Santo (in early 2009 [D. Kalfatak in litt. 2012]); however, it was not recorded during a recent study of bird communities on Espiritu Santo (Bregulla 1992, Kratter et al. 2006) or on a 2010 visit to the area (C. Filardi in litt. 2012).
Historically, it probably occurred on more islands (D. Gibbs in litt 1999), such as Vanikoro and the Reef Islands (but there was no evidence of it during weeks of fieldwork in 1997 and 2014 [G. Dutson pers. obs. 1998, R. Pierce pers. obs 2014]), the Duff Islands, Nendo (where there are sight records from the Whitney expedition in the 1930s [J. Diamond in litt. 1999], but it is now probably extirpated [G. Dutson in litt. 2007]) and the Banks and Torres islands of northern Vanuatu (which are both poorly known [G. Dutson pers. obs. 1998]). The species is probably extinct on Utupua (69 km2): during a brief visit in 1994, none were seen and the villagers of Nembao had no knowledge of it (D. Gibbs in litt 1999).

Ecology

It is believed to forage exclusively on the ground but often perches on low branches and roosts in trees. On Espiritu Santo, it inhabits old-growth rainforest and patches of remnant forest isolated by agricultural land at 300-1,000 m (Bregulla 1992, S. Maturin in litt. 1994, Barré et al. 2011, Dutson 2011). On Tinakula, it inhabits patches of old growth and regenerating forest at 60-260 m (Pierce 2014).

Threats

Introduced rats, cats, dogs and pigs are found throughout Utupua and Espiritu Santo. Tinakula is free of rats and cats but has yellow crazy ants (Pierce 2014). People frequently visit to hunt ground-doves, chickens (Gallus gallus), Chalcophaps indica and fruit bats, as well as gathering fruits, felling trees for canoes, and rearing piglets brought from the mainland (R. Pierce in litt. 2016). Most individuals on Tinakula were collected in 2017 (N. Collar in litt. 2017). Cyclones and volcanic eruptions are a high risk, particularly on Tinakula where a major eruption in October 2017 killed a large part of the species's population (N. Collar in litt. 2017). Forest has been and is being extensively cleared and degraded on Utupua and Espiritu Santo although, on Espiritu Santo, much of the land is too steep for commercial logging and there are few hill villages and gardens above c.500 m. A recently identified threat in Vatthe Conservation Area is the establishment of the invasive vine Merremia peltata, which causes the death of large numbers of canopy trees. Approximately 2,300 ha (92%) of Vatthe forest has been affected, some 1,300 ha of which is too severely affected for control of the vine to be sufficient for restoration, and needs to be replanted (Maturin 2012). The species may also be hunted, and may be out-competed by the Common Emerald Dove Chalcophaps indica in degraded forest habitats (Bregulla 1992, S. Maturin in litt. 1994, G. Dutson pers. obs. 1998, D. Gibbs in litt 1999).

Conservation actions

Conservation Actions Underway
The species occurs in a recently created Community Conservation Area on Mt Tabwesawema in Espiritu Santo. Furthermore, two lowland forests have been protected on Espiritu Santo, but the species has not been found in either. Forest and Bird and EcoLifelihood Development Associates (funded by UNDP/GEF/SGP) are managing a newly established project to develop landowner capacity to control the invasive Merremia peltata in Vatthe Conservation Area. Programmes to strengthen biosecurity to reduce the chances of rat and cat introduction and to research biology and impacts including the effects of Anaplolepis ants on population recruitment are underway (R. Pierce in litt. 2016).

Conservation Actions Proposed
Prepare a species action plan. Survey Tinakula and Espiritu Santo to locate remnant populations and ascertain its distribution, altitudinal range, habitat requirements and abundance. Strengthen biosecurity at any known site. Research impacts of invasive ants and hunting. Search for predator-free islands within the species's range. Determine population levels of introduced mammals around current sites on Espiritu Santo. Assess hunting levels and population trends based on discussions with Espiritu Santo hunters. Advocate creation of more forest reserves on Espiritu Santo. Develop a structured captive breeding and reintroduction programme with the individuals confiscated on the pet market in the Solomon Islands. Investigate hunting control measures through community discussion and awareness programmes.

Identification

23 cm. Small, plump, terrestrial dove. Males have brown upperparts with purple iridescence on wing, grey head and pale pink throat and breast patch. Females are paler with browner throat and breast, and green-glossed upperparts. Immatures are uniformly brown, sometimes with purple on wing. Similar spp. Emerald Dove Chalcophaps indica has green on upperparts, two pale bars on lower mantle and red bill. Voice Slowly accelerating series of up to 15 low woop notes. Hints Usually runs when disturbed, occasionally flushes but best located when calling.

Acknowledgements

Text account compilers
Derhé, M., Westrip, J., Ekstrom, J., Benstead, P., Hermes, C., Dutson, G., Mahood, S., North, A., Stattersfield, A.

Contributors
Filardi, C., Kalfatak, D., Diamond, J., Gibbs, D., Collar, N., Totterman, S., Pierce, R., Maturin, S., O'Brien, M.


Recommended citation
BirdLife International (2020) Species factsheet: Alopecoenas sanctaecrucis. Downloaded from http://www.birdlife.org on 02/12/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 02/12/2020.